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排序方式: 共有1781条查询结果,搜索用时 15 毫秒
1.
Uzun İlhan Orak İkram Yağmur Hatice Karaer Karakaplan Mehmet Yalman Murat 《SILICON》2021,13(12):4703-4713
Silicon - 5-(2,4-dichlorophenyl)-2-furoic acid and anthraquinone-2-carboxylic acid were reacted separately with chitin. The synthesized products were characterized by various spectroscopic methods... 相似文献
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Various image processing applications exploit a model of the human visual system (HVS). One element of HVS-models describes the masking-effect, which is typically parameterized by psycho-visual experiments that employ superimposed sinusoidal stimuli. Those stimuli are oversimplified with respect to real images and can capture only very elementary masking-effects. To overcome these limitations a new psycho-visual test method is proposed. It is based on natural scenery stimuli and operates in the wavelet domain. The collected psycho-visual data is finally used to evaluate the performance of various masking models under conditions as found in real image processing applications like compression. 相似文献
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The present paper studies a feedback regulation problem that arises in at least two different biological applications. The feedback regulation problem under consideration may be interpreted as an adaptive control problem for tuning bifurcation parameters, and it has not been studied in the control literature. The goal of the paper is to formulate this problem and to present some preliminary results. 相似文献
6.
Murat Ozdemir & Hasan Sadikoglu 《International Journal of Food Science & Technology》1998,33(5):439-444
The effects of addition of κ-carrageenan to solutions containing 40% (w/w) sugar substitute on the rheological properties of these systems were investigated at 25 °C using a rotational viscometer at rotational speeds of 6, 12, 30, and 60 rev min−1 . The flow behaviour of the solutions was adequately described by the power law model with or without yield stress. The consistency index ( K ) and the flow behaviour index ( n ) were determined from shear stress vs. shear rate data. The flow parameters of the solutions depended on the carrageenan concentration. The apparent viscosities of the systems decreased with increasing shear rate, indicating pseudoplastic behaviour. The final carrageenan concentration was found to be an effective factor controlling the degree of sliminess of the model food systems studied. 相似文献
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Dishongh T. Basaran C. Cartwright A.N. Ying Zhao Heng Liu 《Advanced Packaging, IEEE Transactions on》2002,25(3):433-438
In this paper the influence of the temperature cycle time history profile on the fatigue life of ball grid array (BGA) solder joints is studied. Temperature time history in a Pentium processor laptop computer was measured for a three-month period by means of thermocouples placed inside the computer. In addition, Pentium BGA packages were subjected to industry standard temperature cycles and also to in-situ measured temperature cycle profiles. Inelastic strain accumulation in each solder joint during thermal cycling was measured by high sensitivity Moire interferometry technique. Results indicate that fatigue life of the solder joint is not independent of the temperature cycle profile used. Industry standard temperature cycle profile leads to conservative fatigue life observations by underestimating the actual number of cycles to failure. 相似文献
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The effect of ancrod-induced defibrinogenation on thrombosis and bleeding time was determined in anesthetized rats. Functional plasma fibrinogen levels were reduced 42, 71, 94 and 93% by ancrod doses of 5, 10, 20 and 30 U/kg, respectively, while a 2.5 U/kg dose was without significant effect. Ancrod inhibited vena cava thrombosis induced by partial stasis of blood flow combined with mild vascular injury. Thrombus weight was decreased 85 and 93% by the 10 and 20 U/kg doses, but was unaffected at lower doses. In contrast, ancrod doses of up to 30 U/kg did not significantly decrease carotid artery thrombi formed in response to oxidative transmural vessel injury. Ancrod caused a dose-dependent increase in bleeding time measured by puncturing small mesenteric arteries with a hypodermic needle. The bleeding time increase was approximately 38% in response to the 2.5 and 5 U/kg doses, and 182% in response to the 10 U/kg dose. These studies demonstrate that ancrod-induced reductions in plasma fibrinogen more effectively inhibit venous compared to arterial thrombosis, although these activities require doses that also increase bleeding time in small arteries. 相似文献
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A method for line interference reduction to be used in signal-averaged electrocardiography (SAECG) systems is proposed and its performance is analyzed. This new method is an adaptation of a previously reported technique for removal of line interference from conventional electrocardiograms. It involves the recording of a line reference signal simultaneous with the lead signals, so that a shifted and sealed version of it can be used to subtract line interference from the leads. It is shown that this line interference subtraction method can reduce line interference effectively and without introducing any additional noise into the ECG signal. It is also shown that Late Potential diagnostic decisions are not altered when this filter is applied. It is recommended that this technique be used in SAECG when line interference is unavoidable 相似文献
10.
Graft copolymers of sodium alginate (NaAlg) with N‐vinyl‐2‐pyrrolidone were prepared using azobisisobutyronitrile as initiator. The graft copolymers (NaAlg‐g‐PVP) were characterized with Fourier transform infrared spectroscopy, elemental analysis, and differential scanning calorimetry. Polymeric hydrogel beads of NaAlg and NaAlg‐g‐PVP were prepared by crosslinking method using glutaraldehyde (GA) as a crosslinker in the hydrochloric acid catalyst (HCl) and these beads were used to deliver anti‐inflammatory drug, indomethacin (IM). Chemical stability of the IM after encapsulation into beads was confirmed by FTIR. Preparation conditions of the NaAlg‐g‐PVP beads were optimized by considering the percentage entrapment efficiency, particle size, swelling capacity and their release data. In vitro release studies were performed in simulated gastric fluid (pH 1.2) for the initial 2 h, followed by simulated intestinal fluid (pH 7.4) for 4 h. Effects of GA concentration, exposure time to GA, drug/polymer (d/p) ratio, and concentration of HCl on the release of IM were discussed. It was observed that IM release from the beads decreased with increasing GA concentration and exposure time. IM release also decreases with increasing d/p ratio and HCl concentration. The highest IM release was obtained to be 77% for beads crosslinked with 0.027M GA. Swelling experiments were also performed to compute molecular mass between crosslinks of the beads. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献